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How Much Does A Glass Extension Cost?

When you decide to extend your home, choosing how to open it up and add more space is a decision that needs serious thought. With a glass house extension finish going far beyond what any traditional home extension could offer, one crucial question remains: How much does a glass extension cost?

This expert guide will cover all the details you need to know about how much a glass extension is likely to cost, as well as look at factors that can affect the cost and how you can save money along the way.

How much does a glass extension cost?

The architectural glass used to build such an elegant structure means it can bring in natural light. A glass house extension will brighten the darkest of homes with a thoroughly modern, minimalist design giving you a sense of outdoor living. But, due to their seamless finish, the popularity of glass extensions has risen recently, but not to the detriment of their exclusivity. 

So once your decision is made, how much does a glass house extension really cost? Final costs will always depend on your requirements and preferences, but GlasSpace customers can spend between £20,000 and £250,000 depending on the size, shape, and style of glass extension needed. 

These costs will include the supply of structural glass used for the roof and walls for the extension and our installation experience and quality service. But outside factors also need to be considered. These can consist of architects, structural engineers, or specialist glass extension designers who can plan and design your glass extension to your chosen specifications and take care of any structural issues, regulatory requirements, or planning applications.

Now you understand how much a glass extension could cost, contact us today to start your project by discussing your ideal glass extension in a complimentary consultation with our design team. You can also view some of our previous glass extension projects for design inspiration, to compare styles, and show the flexibility a glass extension can give you.

What can affect the cost of building a glass extension?

Glass house extensions can be expensive but will give you a beautiful, contemporary space that significantly adds to your home’s value. But certain factors can affect the overall cost and make the process more – or less – expensive, depending on what you need. We touched on some of these factors above, but here are some other considerations that could impact costs and budget.


The size of your glass extension will always have a defining part to play in your overall costs. Naturally, the larger your space will be, the more glass will need to be used and with that comes increased costs to manufacture and install your glass extension.


Your chosen glass extension style depends on the size you need or the available space. While a full glass house extension can offer an architectural statement for additional living space or a dedicated dining room, a side return kitchen extension could give you a cost-effective alternative with an equally stunning finish.


We use high-performance architectural SunGuard® glass with 70/37 solar control for light transmission and low solar heat gain for all walls, roofs, and sliding or hinged doors of your glass extension. While the glass maintains consistent temperatures all year round, you can choose from various colours and appearances to suit your property.

Ease of access

Proper, clear property access is essential when installing your glass extension. The glass panels are expensive, heavy, and awkward to manoeuvre, so your installation team may need to use additional methods, such as a crane, to get the glass to the back or side of your property beforehand. Machine or crane hire can add to your costs depending on size and hire period.

Structural engineering and architect fees

Using a qualified structural engineer or architect to oversee or plan your glass house extension will add to your overall costs, with fees dependent on the project’s complexity. You should expect to pay an average of £100 per hour for a structural engineer and similar for an architect. However, being hired for a fixed project time may save costs. 

Planning permissions and building regulations approval

The beauty of a glass house extension is that, in most circumstances, you won’t need planning permission as it will come under your permitted development rights. However, planning permission is required if you own Grade I or II listed property, though planning officers prefer glass house extensions thanks to their discreet and aesthetically pleasing style. 

While dependant on the size and complexity of your extension and your local authority, planning costs can include:

– Building Regulations application: up to £300

– Building inspections: up to £650

– Planning applications: £206

Your architect will have the experience to deal with all these requirements on your behalf, adding the costs to their final fee.

How can I save money on my glass extension?

Any extension to your property will take commitment and a sizeable investment, whether you build a large, new room or use a smaller, existing space. But going into your project with the mindset of saving money might not help you achieve what you need. Once you go ahead, the key to saving money is knowing all your project details. This will allow you to plan for contingencies that could be expensive.

Every glass extension is bespoke and yours will be unique to your property. Glass is expensive to make and difficult to handle, so any adjustments needed can be costly. While it might seem counterintuitive to spend money on architects fees up front, having precision plans and measurements will undoubtedly save you money and heartache in the long run. 

Reveal your perfect glass extension with GlasSpace

Many factors are involved in calculating how much a glass extension will cost. But the sophistication and elegance of a high-end, custom-designed glass house extension can open up your home, regardless of size, layout, age, or style, giving you a timeless living space flooded with natural light. 

When you want to extend your home, our GlasSpace team has all the experience, knowledge, and expertise you need to help you make the right choice. For more information about a contemporary glass house extension’s design, construction, and costs, contact us today and get your no-obligation, free quote to start extending your home in style.

At glasspace we encourage you to take advantage of our complimentary design consultation with an advisor who will have the expertise and knowledge to assist you with a structure that is right for you.

Taking your brief and ideas we can design for you. If you have an Architect or designer, we will collaborate to ensure your new bespoke glass structure is the best it can be.

GlasSpace’s structures are unique and not made up of standard parts so designers have the freedom to express your idea.